CVE-2021-47613

Guest memory corruption via premature virtio-I2C buffer release

Published Jun 19, 2024 · Updated Aug 5, 2026

Use-after-free in Linux kernel 5.15 through 5.15.9 allows local users to corrupt guest memory or place incorrect data on the I2C bus. The virtio-I2C notify callback assumes every queued buffer is complete, causing the request path to free buffers that the device can still access. Exploitation requires local low-privileged access to a guest using the virtio-I2C frontend, with consequences confined to guest memory and I2C traffic.

CVSS severity7.8
High
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux kernel 5.15 through 5.15.9 allows local users to corrupt guest memory or place incorrect data on the I2C bus. The virtio-I2C notify callback assumes every queued buffer is complete, causing the request path to free buffers that the device can still access. Exploitation requires local low-privileged access to a guest using the virtio-I2C frontend, with consequences confined to guest memory and I2C traffic.

The record

CVE
CVE-2021-47613
Published
Jun 19, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 19, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3cfc88380413d20f777dc6648a38f683962e52bf <9cbb957441ed8873577d7d313a3d79d69f1dad5c
  2. Affected versionversion=3cfc88380413d20f777dc6648a38f683962e52bf <b503de239f62eca898cfb7e820d9a35499137d22
  3. Affected versionversion=5.15

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3cfc88380413d20f777dc6648a38f683962e52bf <9cbb957441ed8873577d7d313a3d79d69f1dad5c; version=3cfc88380413d20f777dc6648a38f683962e52bf <b503de239f62eca898cfb7e820d9a35499137d22; version=5.15

Published CVSS scores

7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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